Vector simple_form error notification to flash

simple_form-error-notification-to-flash.rb

# A https://github.com/plataformatec/simple_form puts it's alert box inside of the form instead 
#  of using the flash object. This may look clunky depending on how the various backgrounds are set up on the page.

# E.g. in a view, f.error_notification puts the alert within the form instead of above 
#  it where flash info goes as per the layout
<%= simple_form_for(resource, as: resource_name, url: confirmation_path(resource_name), html: { method: :post }) do |f| %>
  <%= f.error_notification %>
  <%= f.full_error :confirmation_token %>

  <div class="form-inputs">
    <%= f.input :email, required: true, autofocus: true %>
  </div>

  <div class="form-actions">
    <%= f.button :submit, "Send confirmation instructions", class: "btn-large btn-submit" %>
  </div>
  <%= render "devise/shared/nav" %>
<% end %>

# By deriving a custom form builder class and overriding a few things we can easily stick these 
#  messages in the flash object insted and handle their output in the layout file. 
#  Here are the files neeeded:

# config/initializers/z300_custom_form.rb
require 'custom_form'

module SimpleForm::ActionViewExtensions::FormHelper

  def simple_form_for_with_custom(object, *args, &block)
    options = args.extract_options!
    simple_form_for_without_custom(object, *(args << options.merge(builder: ::CustomForm::FormBuilder)), &block)
  end

  alias_method_chain :simple_form_for, :custom

end

# lib/custom_form.rb
require 'simple_form'
require 'custom_form/form_builder'
require 'custom_form/error_notification'

module CustomForm

end

# lib/custom_form/error_notification.rb
module CustomForm
  class ErrorNotification < SimpleForm::ErrorNotification

    def render
      if has_errors?
        # put message right into the flash instedd of rendering it into a div within the form
        template.flash.now[:alert] = error_message
      end

      ''
    end

    protected

    def translate_error_notification
      lookups = []
      lookups << :"#{object_name}"
      lookups << :default_message
      lookups << "Please review the problems below:"
      # added :count option so the message is properly pluralized
      I18n.t(lookups.shift, scope: :"simple_form.error_notification", default: lookups, count: errors.count)
    end

  end
end

# config/locales/simple_form.en.yml

en:
  simple_form:
    error_notification:
      default_message: # remove message from here and nest the variants by counta
        zero: ''
        one: "Please fix the highlighted issue"
        other: "Please fix the highlighted issues"